A mobile or cellular telephone system is an example of a wireless communications system for transmitting and receiving data between wireless end user equipment or applications and wireless network equipment. Transmitted and received data may be in the form of data packets. Transmitted and received data packets may be in a variety of formats and may include a variety of different types of data, such as voice data, binary data, video data, and the like.
In a typical wireless communications system, wireless transmissions take place between wireless user equipment, such as a cellular telephone or other device using wireless technology, and nodes of the wireless communications network. Transmissions from the network nodes to the user equipment are referred to as downlink transmissions or forward link transmissions. Transmissions from the user equipment to the network nodes are known as uplink transmissions or reverse link transmissions.
Some known or proposed wireless communications networks may provide different types of network nodes for providing wireless communications with wireless user equipment. For example, a heterogeneous Long Term Evolution Advanced, LTE-A, wireless communications network employs both regular nodes, such as conventional evolved Universal Mobile Telecommunications System, UMTS, Terrestrial Radio Access Network, E-UTRAN, Node B nodes, and relay nodes for communications with wireless user equipment. In this case, the regular nodes and relay nodes perform similar functions in establishing and carrying out wireless communications with user equipment. The main difference between the regular nodes and relay nodes is the transmission power. For example, in a Long Term Evolution Advanced, LTE-A, network, there likely will be a large difference between E-UTRAN Node B transmission power, for example, 46 dBm, and relay node transmission power, for example, 30 dBm or 36 dBm.
At the initiation of wireless communications between wireless user equipment and a wireless communications network, or as the user equipment moves, the user equipment selects the network node with which it will communicate. This node is known as the serving node. The serving node is used for both uplink and downlink communications between the user equipment and the network. Typically, the user equipment will attempt to select the best network node to operate as the serving node based on downlink signal strength. Thus, user equipment typically will select the network node from which the user equipment receives the strongest downlink signal as the serving node. In a wireless communications network that provides both standard and relay nodes, either a standard node, such as a conventional E-UTRAN node B node, or a relay node may be selected by the user equipment as the serving node based on received downlink signal strength at the user equipment.